1. Field of the Invention
The present invention relates to a method for forming a microcrystalline semiconductor film, a method for manufacturing a semiconductor device including the microcrystalline semiconductor film, and a display device.
In this specification, a semiconductor device means all types of devices which can function by utilizing semiconductor characteristics, and a display device, an electro-optical device, a photoelectric conversion device, a semiconductor circuit, and an electronic device are all semiconductor devices.
2. Description of the Related Art
As one type of field-effect transistor, a thin film transistor whose channel region is formed using a semiconductor film which is formed over a substrate having an insulating surface is known. Techniques in which amorphous silicon, microcrystalline silicon, or polycrystalline silicon is used for the semiconductor film which is used for the channel region of the thin film transistor have been disclosed (see Patent Documents 1 to 5). A typical application of the thin film transistor is a liquid crystal television device, in which the thin film transistor is practically used as a switching transistor in each pixel in a display screen.
A photoelectric conversion device has been developed in which microcrystalline silicon as crystalline silicon that can be formed by a plasma CVD method is used for a semiconductor film having a function of photoelectric conversion (for example, see Patent Document 6).